Cytochrome mixed function oxygenases

The enzymes appear to be cytochrome Ph50 mixed-function oxygenases with electron transfer components similar to those found in liver (19,20). 

Berrigan MJ, Gurtoo HL, Sharma SD, et al. 1980. Protection by N- acetylcystein of cyclophosphamide metabolism-related in vivo depression of mixed function oxygenase activity and in vitro denaturation of cytochrome P-450. Biochem Biophys Res Commun 93 797-803. 

The NADPH-cytochrome P-450 system, commonly known as the mixed-function oxygenase (MFO) system, is the most important enzyme system involved in the Phase I oxidation reactions. Cytochrome P-450 system, localized in the smooth endoplasmic reticulum of cells of most mammalian tissues, is particularly abundant in the liver. This system contains a number of isozymes which are versatile in that they catalyze many types of reactions including aliphatic and aromatic hydroxylations and epoxidations,... 

The potential of tricyclohexyltins to modify the inducibility of cytochrome P450 by various substances, such as 3-methylcholanthrene, is of considerable toxicological importance. Significant metabolic interactions can result from a combination of environmental chemicals and drugs that produce alterations in heme and mixed function oxygenase activity, suggesting that more research is needed on interaction effects of organotins with other environmental substances or contaminants. 

Batel R, Bihari N, Kurelec B, Muller WEG, Zahn RK (1983) Presence of mixed function oxygenases in some marine invertebrates. Thalassia Jugoslav 19 23-29 Batel R, Bihari N, Zahn RK (1986) Purification and characterization of a single form of cytochrome P-450 from the spiny crab Maja crispata. Comp Biochem Physiol 83C 165-170 Batel R, Bihari N, Zahn RK (1988) 3-methylcholanthrene does induce mixed function oxidase activity in hepatopancreas of spiny crab Maja crispata. Comp Biochem Physiol 90C 435-438 Bauer JE, Kerr RP, Bautista MF, Decker C J, Capone DG (1988) Stimulation of microbial activities and polycyclic aromatic hydrocarbon degradation in marine sediments inhabited by Capitella capitata. Mar Env Res 25 63-84... 

Electron exchange between the two pathways is indicated by the double arrow which expresses the idea that NADH may serve via cytochrome bs as a second electron donor for mixed function oxygenases. Dallner et al. [85] have found that component x is low and may be limiting in detoxication reactions of neonatal rats. Component x is measured by reduction of neotetrazolium. 

Stegeman, J.J. 1978. Influence of environmental contamination on cytochrome P-450 mixed-function oxygenases in fish implications for recovery in the Wild Harbor Marsh. Journal of the Fisheries Research Board of Canada 35 668-674. 

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